Screw it! I'm tired of making meme comments!
If the speed limit is 45 mph, you only save:
     8 seconds per mile by going 50 mph
     14.5 seconds per mile by going 55 mph
     20 seconds per mile by going 60 mph
If the speed limit is 50 mph, you only save:
     6.5 seconds per mile by going 55 mph
     12 seconds per mile by going 60 mph
     16.6 seconds per mile by going 65 mph
If the speed limit is 55 mph, you only save:
     5.5 seconds per mile by going 60 mph
     10.1 seconds per mile by going 65 mph
     14.1 seconds per mile by going 70 mph
     17.5 seconds per mile by going 75 mph
If the speed limit is 60 mph, you only save:
     4.6 seconds per mile by going 65 mph
     9.6 seconds per mile by going 70 mph
     12 seconds per mile by going 75 mph
     15 seconds per mile by going 80 mph
If the speed limit is 65 mph, you only save:
     4 seconds per mile by going 70 mph
     7.4 seconds per mile by going 75 mph
     10.4 seconds per mile by going 80 mph
     13 seconds per mile by going 85 mph
If the speed limit is 70 mph, you only save:
     3.4 seconds per mile by going 75 mph
     6.4 seconds per mile by going 80 mph
     9 seconds per mile by going 85 mph
     11.4 seconds per mile by going 90 mph
If the speed limit is 75 mph, you only save:
     3 seconds per mile by going 80 mph
     5.6 seconds per mile by going 85 mph
     8 seconds per mile by going 90 mph
     10.1 seconds per mile by going 95 mph
If the speed limit is 80 mph, you only save:
     2.6 seconds per mile by going 85 mph
     5 seconds per mile by going 90 mph
     7.1 seconds per mile by going 95 mph
     9 seconds per mile by going 100 mph